Corvette Needs New Wiring

Now that the engine was finally working, we had time to concentrate on other things. The heater box and some air conditioner ducts had cracks so I took them home and my friend went through the wiring harnesses. I fixed the ducts with some fiberglass and then painted them. Perhaps they actually stay in place and won't leak any more when I get them in the car.

Meanwhile my friend made some interesting discoveries from the wiring. He was checking the AC wires when he noticed that there were sparks flying from somewhere. Quickly he found that a loose black ground wire made them when it hit the frame! WTF? He went through the wires in more detail and found that the AC ground wire was connected to the positive terminal of the starter motor. Which in turn was connected directly to the battery! This had caused a massive short circuit inside the harnesses.

After finding this he removed the AC, ignition and headlamp harnesses from the car because we could not trust them anymore. It was a miracle that the car even ran after the damage from the short circuit or that the car had not burned completely. There must have been quite a lot of smoke after this electrical genius had connected the battery...

I had to think for a while for what to do. I could order all new harnesses but they would still be as badly designed as the original and they cost quite a lot. I had been thinking about adding relays for the headlamps at some point and I also needed an electrical fan for the radiator because the original fan clutch was not working plus the fan shroud was missing. This would be a good time to add these!

In the end I redesigned the whole headlamp harness by adding a central power junction that fed two headlamp relays and a fan relay and sensor. My friend also rebuild the AC and ignition harnesses so every wire was replaced with new ones in the engine bay. This just left the dash harness. It was way too complicated to rebuild by hand so I had to buy a new one. I did some searching and found a shop called Full Throttle Corvette from eBay that had the cheapest price and would ship to Finland. After these changes every wire would be new in the car.

I'll write another post about the redesigned headlamp harness next...